Most of the health concerns associated with polycythemia vera are caused by the blood being thicker as a result of the increased red blood cells. It is more common in the elderly and may be symptomatic or asymptomatic. Common signs and symptoms include itching (pruritus), and severe burning pain in the hands or feet that is usually accompanied by a reddish or bluish coloration of the skin. Patients with polycythemia vera are more likely to have gouty arthritis. Treatment consists primarily of phlebotomy.

Contents

Erythromelalgia is a rare symptom of PV, here present in a patient with longstanding polycythemia vera. Note reddish limbs and swelling.

People with polycythemia vera can be asymptomatic.[2] A classic symptom of polycythemia vera is pruritus or itching, particularly after exposure to warm water (such as when taking a bath),[3] which may be due to abnormal histamine release[4][5] or prostaglandin production.[6] Such itching is present in approximately 40% of patients with polycythemia vera.[7]Gouty arthritis may be present in up to 20% of patients.[7]Peptic ulcer disease is also common in patients with polycythemia vera; most likely due to increased histamine from mast cells, but may be related to an increased susceptibility to infection with the ulcer-causing bacterium H. pylori.[8] Another possible mechanism for the development for peptic ulcer is increased histamine release and gastric hyperacidity related with polycythemia vera.

A classic symptom of polycythemia vera (and the related myeloproliferative disease essential thrombocythemia) is erythromelalgia.[9] This is a burning pain in the hands or feet, usually accompanied by a reddish or bluish coloration of the skin. Erythromelalgia is caused by an increased platelet count or increased platelet "stickiness" (aggregation), resulting in the formation of tiny blood clots in the vessels of the extremity; it responds rapidly to treatment with aspirin.[10][11]

Polycythemia vera (PCV), being a primary polycythemia, is caused by neoplastic proliferation and maturation of erythroid, megakaryocytic and granulocytic elements to produce what is referred to as panmyelosis. In contrast to secondary polycythemias, PCV is associated with a low serum level of the hormone erythropoietin (EPO). Instead, PCV cells often carry activating mutation in the tyrosine kinase (JAK2) gene, which acts in signaling pathways of the EPO-receptor, making those cells proliferate independent from EPO.[12]

In primary polycythemia, there may be 8 to 9 million and occasionally 11 million erythrocytes per cubic millimeter of blood (a normal range for adults is 4-6), and the hematocrit may be as high as 70 to 80%. In addition, the total blood volume sometimes increases to as much as twice normal. The entire vascular system can become markedly engorged with blood, and circulation times for blood throughout the body can increase up to twice the normal value. The increased numbers of erythrocytes can cause the viscosity of the blood to increase as much as five times normal. Capillaries can become plugged by the very viscous blood, and the flow of blood through the vessels tends to be extremely sluggish.

The disease appears more common in Jews of European extraction than in most non-Jewish populations. Some familial forms of polycythemia vera are noted, but the mode of inheritance is not clear.

A mutation in the JAK2 kinase (V617F) is strongly associated with polycythemia vera.[14][15]JAK2 is a member of the Janus kinase family and makes the erythroid precursors hypersensitive to erythropoietin (EPO). This mutation may be helpful in making a diagnosis or as a target for future therapy.

Following history and examination, the British Committee for Standards in Haematology (BCSH) recommend the following tests are performed:

Untreated, polycythemia vera can be fatal.[16][17] Research has found that the "1.5-3 years of median survival in the absence of therapy has been extended to at least 10-20 years because of new therapeutic tools."[18]

As the condition cannot be cured, treatment focuses on treating symptoms and reducing thrombotic complications by reducing the erythrocyte levels.

Phlebotomy is one form of treatment, which often may be combined with other therapies. The removal of blood from the body induces iron deficiency, thereby decreasing the haemoglobin / hematocrit level, and reducing the risk of blood clots. Phlebotomy is typically performed to bring their hematocrit (red blood cell percentage) down below 45 for men or 42 for women.[19] It has been observed that phlebotomy also improves cognitive impairment.[20]

Low dose aspirin (75–81 mg daily) is often prescribed. Research has shown that aspirin reduces the risk for various thrombotic complications.

Chemotherapy for polycythemia may be used, either for maintenance, or when the rate of bloodlettings required to maintain normal hematocrit is not acceptable, or when there is significant thrombocytosis or intractable pruritus. This is usually with a "cytoreductive agent" (hydroxyurea, also known as hydroxycarbamide).

The tendency of some practitioners to avoid chemotherapy if possible, especially in young patients, is a result of research indicating possible increased risk of transformation to acute myelogenous leukemia (AML). While hydroxyurea is considered safer in this aspect, there is still some debate about its long-term safety.[21]

In the past, injection of radioactive isotopes (principally phosphorus-32) was used as another means to suppress the bone marrow. Such treatment is now avoided due to a high rate of AML transformation.

Polycythemia vera occurs in all age groups,[27] although the incidence increases with age. One study found the median age at diagnosis to be 60 years,[7] while a Mayo Clinic study in Olmsted County, Minnesota found that the highest incidence was in people aged 70–79 years.[28] The overall incidence in the Minnesota population was 1.9 per 100,000 person-years, and the disease was more common in men than women.[28] A cluster around a toxic site was confirmed in northeast Pennsylvania in 2008. [29]

1.
Red blood cells
–
RBCs take up oxygen in the lungs, or gills of fish, and release it into tissues while squeezing through the bodys capillaries. The cytoplasm of erythrocytes is rich in hemoglobin, a biomolecule that can bind oxygen and is responsible for the red color of the cells. In humans, mature red cells are flexible and oval biconcave disks. They lack a nucleus and most organelles, in order to accommodate maximum space for hemoglobin, they can be viewed as sacks of hemoglobin. Approximately 2.4 million new erythrocytes are produced per second in human adults, the cells develop in the bone marrow and circulate for about 100–120 days in the body before their components are recycled by macrophages. Each circulation takes about 60 seconds, approximately a quarter of the cells in the human body are red blood cells. Nearly half of the volume is red blood cells. Red blood cells are known as RBCs, red cells, red blood corpuscles, haematids. Packed red blood cells are red blood cells that have donated, processed. Almost all vertebrates, including all mammals and humans, have red blood cells, red blood cells are cells present in blood in order to transport oxygen. The only known vertebrates without red blood cells are the crocodile icefish, they live in very cold water. While they no longer use hemoglobin, remnants of hemoglobin genes can be found in their genome, oxygen can easily diffuse through the red blood cells cell membrane. Myoglobin, a related to hemoglobin, acts to store oxygen in muscle cells. The color of red cells is due to the heme group of hemoglobin. However, blood can appear bluish when seen through the vessel wall, pulse oximetry takes advantage of the hemoglobin color change to directly measure the arterial blood oxygen saturation using colorimetric techniques. Hemoglobin also has a high affinity for carbon monoxide, forming carboxyhemoglobin which is a very bright red in color. Flushed, confused patients with a reading of 100% on pulse oximetry are sometimes found to be suffering from carbon monoxide poisoning. The red blood cells of mammals are typically shaped as disks, flattened and depressed in the center, with a dumbbell-shaped cross section

2.
White blood cells
–
White blood cells, also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from multipotent cells in the bone known as hematopoietic stem cells. Leukocytes are found throughout the body, including the blood and lymphatic system, all white blood cells have nuclei, which distinguishes them from the other blood cells, the anucleated red blood cells and platelets. Types of white cells can be classified in standard ways. Two pairs of broadest categories classify them either by structure or by cell division lineage and these broadest categories can be further divided into the five main types, neutrophils, eosinophils, basophils, lymphocytes, and monocytes. These types are distinguished by their physical and functional characteristics, further subtypes can be classified, for example, among lymphocytes, there are B cells, T cells, and NK cells. The number of leukocytes in the blood is often an indicator of disease, the normal white cell count is usually between 4 × 109/L and 11 × 109/L. In the US this is expressed as 4,000 to 11,000 white blood cells per microliter of blood. They make up approximately 1% of the blood volume in a healthy adult. However, this 1% of the blood makes a difference to health. An increase in the number of leukocytes over the limits is called leukocytosis. It is normal when it is part of immune responses. It is occasionally abnormal, when it is neoplastic or autoimmune in origin, a decrease below the lower limit is called leukopenia. The name white blood cell derives from the appearance of a blood sample after centrifugation. White cells are found in the buff, a thin, typically white layer of nucleated cells between the red blood cells and the blood plasma. The scientific term leukocyte directly reflects its description and it is derived from the Greek roots leuk- meaning white and cyt- meaning cell. The buffy coat may sometimes be green if there are large amounts of neutrophils in the sample, all white blood cells are nucleated, which distinguishes them from the anucleated red blood cells and platelets. Types of leukocytes can be classified in standard ways, two pairs of broadest categories classify them either by structure or by cell lineage

3.
Platelets
–
Platelets, also called thrombocytes, are a component of blood whose function is to stop bleeding by clumping and clotting blood vessel injuries. Platelets have no nucleus, they are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow. These unactivated platelets are biconvex discoid structures, 2–3 µm in greatest diameter, platelets are found only in mammals, whereas in other animals thrombocytes circulate as intact mononuclear cells. On a stained blood smear, platelets appear as purple spots. The smear is used to examine platelets for size, shape, qualitative number, the ratio of platelets to red blood cells in a healthy adult is 1,10 to 1,20. The main function of platelets is to contribute to hemostasis, the process of stopping bleeding at the site of interrupted endothelium and they gather at the site and unless the interruption is physically too large, they plug the hole. First, platelets attach to substances outside the interrupted endothelium, adhesion, second, they change shape, turn on receptors and secrete chemical messengers, activation. Third, they connect to each other through receptor bridges, aggregation, formation of this platelet plug is associated with activation of the coagulation cascade with resultant fibrin deposition and linking. These processes may overlap, the spectrum is from a predominantly platelet plug, or white clot to a predominantly fibrin clot, the final result is the clot. Some would add the subsequent clot retraction and platelet inhibition as fourth and fifth steps to the completion of the process, low platelet concentration is thrombocytopenia and is due to either decreased production or increased destruction. Elevated platelet concentration is thrombocytosis and is either congenital, reactive, or due to unregulated production, a disorder of platelet function is a thrombocytopathy. An arterial thrombus may partially obstruct blood flow, causing downstream ischemia, or may completely obstruct it, george Gulliver in 1841 drew pictures of platelets using the twin lens microscope invented in 1830 by Joseph Jackson Lister. This microscope improved resolution sufficiently to make it possible to see platelets for the first time, william Addison in 1842 drew pictures of a platelet-fibrin clot. Lionel Beale in 1864 was the first to publish a drawing showing platelets, max Schultze in 1865 described what he called spherules, which he noted were much smaller than red blood cells, occasionally clumped, and were sometimes found in collections of fibrin material. Queens College, Birmingham physician Dr Richard Hill Norris was the first to describe the action of platelets in 1880, giulio Bizzozero in 1882 studied the blood of amphibians microscopically in vivo. He named Schultzs spherules piastrine, little plates, william Osler observed them and, in published lectures in 1886, called them a third corpuscle and a blood plaque and described them as a colorless protoplasmic disc. Thrombocytes are cells found in the blood of non-mammalian vertebrates and they are the functional equivalents of platelets, but circulate as intact mononuclear cells, and are not simply cytoplasmic fragments of bone marrow megakaryocytes. In some contexts, the thrombus is used interchangeably with the word clot

4.
Asymptomatic
–
In medicine, a disease is considered asymptomatic if a patient is a carrier for a disease or infection but experiences no symptoms. A condition might be if it fails to show the noticeable symptoms with which it is usually associated. Asymptomatic infections are also called subclinical infections, other diseases might be considered subclinical if they present some but not all of the symptoms required for a clinical diagnosis. The term clinically silent is also used, knowing that a condition is asymptomatic is important because, It may develop symptoms later and so require watch and wait or early treatment. It may resolve itself or become benign and it is required that a person undergoes treatment so it does not cause later medical problems such as high blood pressure and hyperlipidaemia. Be alert to possible problems, asymptomatic hypothyroidism makes a person vulnerable to Wernicke-Korsakoff syndrome or beri-beri following intravenous glucose, the affected person may be infectious and unknowingly spread the infection to others. An example of a disease is Cytomegalovirus which is a member of the herpes virus. It is estimated that 1% of all newborns are infected with CMV, in some diseases, the proportion of asymptomatic cases can be important. For example in multiple sclerosis it is estimated that around 25% of the cases are asymptomatic, asymptomatic conditions may not be discovered until the patient undergoes medical tests. Some people may remain asymptomatic for a long period of time. If a patient is asymptomatic, precautionary steps must be taken, a patients individual genetic makeup may delay or prevent the onset of symptoms. Some diseases are defined only clinically, like AIDS being opposed to HIV infection, therefore it makes no sense to speak about asymptomatic AIDS. This concept of clinically defined diseases is related in some way to the concept of syndrome and these are conditions for which there is a sufficient number of documented individuals that are asymptomatic that it is clinically noted. For a complete list of asymptomatic infections see subclinical infection

5.
Prostaglandin
–
The prostaglandins are a group of physiologically active lipid compounds having diverse hormone-like effects in animals. Prostaglandins have been found in almost every tissue in humans and other animals and they are derived enzymatically from fatty acids. Every prostaglandin contains 20 carbon atoms, including a 5-carbon ring and they are a subclass of eicosanoids and of the prostanoid class of fatty acid derivatives. The structural differences between prostaglandins account for their different biological activities, a given prostaglandin may have different and even opposite effects in different tissues in some cases. The ability of the same prostaglandin to stimulate a reaction in one tissue and they act as autocrine or paracrine factors with their target cells present in the immediate vicinity of the site of their secretion. Prostaglandins differ from endocrine hormones in that they are not produced at a specific site, prostaglandins are powerful locally acting vasodilators and inhibit the aggregation of blood platelets. Through their role in vasodilation, prostaglandins are also involved in inflammation and they are synthesized in the walls of blood vessels and serve the physiological function of preventing needless clot formation, as well as regulating the contraction of smooth muscle tissue. Conversely, thromboxanes are vasoconstrictors and facilitate platelet aggregation and their name comes from their role in clot formation. Specific prostaglandins are named with a letter followed by a number, for example, prostaglandin E1 is abbreviated PGE1 or PGE1, and prostaglandin I2 is abbreviated PGI2 or PGI2. The name prostaglandin derives from the prostate gland, when prostaglandin was first isolated from seminal fluid in 1935 by the Swedish physiologist Ulf von Euler, and independently by M. W. Goldblatt, it was believed to be part of the prostatic secretions, in fact, prostaglandins are produced by the seminal vesicles. It was later shown that many other tissues secrete prostaglandins for various functions, the first total syntheses of prostaglandin F2α and prostaglandin E2 were reported by E. J. Corey in 1969, an achievement for which he was awarded the Japan Prize in 1989. In 1971, it was determined that aspirin-like drugs could inhibit the synthesis of prostaglandins, the biochemists Sune K. Bergström, Bengt I. Samuelsson and John R. Vane jointly received the 1982 Nobel Prize in Physiology or Medicine for their research on prostaglandins, prostaglandins are found in most tissues and organs. They are produced by almost all nucleated cells and they are autocrine and paracrine lipid mediators that act upon platelets, endothelium, uterine and mast cells. They are synthesized in the cell from the fatty acids. An intermediate arachidonic acid is created from diacylglycerol via phospholipase-A2, then brought to either the cyclooxygenase pathway or the lipoxygenase pathway, prostaglandins were originally believed to leave the cells via passive diffusion because of their high lipophilicity. The release of prostaglandin has now also shown to be mediated by a specific transporter, namely the multidrug resistance protein 4

6.
Red blood cell
–
RBCs take up oxygen in the lungs, or gills of fish, and release it into tissues while squeezing through the bodys capillaries. The cytoplasm of erythrocytes is rich in hemoglobin, a biomolecule that can bind oxygen and is responsible for the red color of the cells. In humans, mature red cells are flexible and oval biconcave disks. They lack a nucleus and most organelles, in order to accommodate maximum space for hemoglobin, they can be viewed as sacks of hemoglobin. Approximately 2.4 million new erythrocytes are produced per second in human adults, the cells develop in the bone marrow and circulate for about 100–120 days in the body before their components are recycled by macrophages. Each circulation takes about 60 seconds, approximately a quarter of the cells in the human body are red blood cells. Nearly half of the volume is red blood cells. Red blood cells are known as RBCs, red cells, red blood corpuscles, haematids. Packed red blood cells are red blood cells that have donated, processed. Almost all vertebrates, including all mammals and humans, have red blood cells, red blood cells are cells present in blood in order to transport oxygen. The only known vertebrates without red blood cells are the crocodile icefish, they live in very cold water. While they no longer use hemoglobin, remnants of hemoglobin genes can be found in their genome, oxygen can easily diffuse through the red blood cells cell membrane. Myoglobin, a related to hemoglobin, acts to store oxygen in muscle cells. The color of red cells is due to the heme group of hemoglobin. However, blood can appear bluish when seen through the vessel wall, pulse oximetry takes advantage of the hemoglobin color change to directly measure the arterial blood oxygen saturation using colorimetric techniques. Hemoglobin also has a high affinity for carbon monoxide, forming carboxyhemoglobin which is a very bright red in color. Flushed, confused patients with a reading of 100% on pulse oximetry are sometimes found to be suffering from carbon monoxide poisoning. The red blood cells of mammals are typically shaped as disks, flattened and depressed in the center, with a dumbbell-shaped cross section

7.
Megakaryocyte
–
A megakaryocyte is a large bone marrow cell with a lobulated nucleus responsible for the production of blood thrombocytes, which are necessary for normal blood clotting. Megakaryocytes normally account for 1 out of 10,000 bone marrow cells, owing to variations in combining forms and spelling, synonyms include megalokaryocyte and megacaryocyte. In general, megakaryocytes are 10 to 15 times larger than a red blood cell. During its maturation, the megakaryocyte grows in size and replicates its DNA without cytokinesis in a process called endomitosis. As a result, the nucleus of the megakaryocyte can become large and lobulated. In some cases, the nucleus may contain up to 64N DNA, the cytoplasm, just as the platelets that bud off from it, contains α-granula and Dense bodies. Megakaryocytes are derived from stem cell precursor cells in the bone marrow. They are produced primarily by the liver, kidney, spleen and these multipotent stem cells live in the marrow sinusoids and are capable of producing all types of blood cells depending on the signals they receive. The primary signal for megakaryocyte production is thrombopoietin or TPO, TPO is sufficient but not absolutely necessary for inducing differentiation of progenitor cells in the bone marrow towards a final megakaryocyte phenotype. Other molecular signals for megakaryocyte differentiation include GM-CSF, IL-3, IL-6, IL-11, chemokines. the megakaryocyte develops through the following lineage, CFU-Me -> megakaryoblast -> promegakaryocyte -> megakaryocyte. The cell eventually reaches megakaryocyte stage and loses its ability to divide, however, it is still able to replicate its DNA and continue development, becoming polyploid. The cytoplasm continues to expand and the DNA complement can increase up to 64N in human, once the cell has completed differentiation and become a mature megakaryocyte, it begins the process of producing platelets. The maturation process occurs via endomitotic synchronous replication whereby the cytoplasmic volume enlarges as the number of chromosomes multiplies without cellular division, the cell ceases its growth at 4N, 8N or 16N, becomes granular, and begins to produce platelets. Thrombopoietin plays a role in inducing the megakaryocyte to form small proto-platelet processes, platelets are held within these internal membranes within the cytoplasm of megakaryocytes. There are two proposed mechanisms for platelet release, in one scenario, these proto-platelet processes break up explosively to become platelets. Alternatively, the cell may form platelet ribbons into blood vessels, the ribbons are formed via pseudopodia and they are able to continuously emit platelets into circulation. In either scenario, each of these processes can give rise to 2000-5000 new platelets upon breakup. Overall, 2/3 of these newly produced platelets will remain in circulation while 1/3 will be sequestered by the spleen, after budding off platelets, what remains is mainly the cell nucleus

8.
Granulocyte
–
Granulocytes are a category of white blood cells characterized by the presence of granules in their cytoplasm. They are also called polymorphonuclear leukocytes because of the shapes of the nucleus. This distinguishes them from the mononuclear agranulocytes, in common parlance, the term polymorphonuclear leukocyte often refers specifically to neutrophil granulocytes, the most abundant of the granulocytes, the other types have lower numbers. Granulocytes are produced via granulopoiesis in the bone marrow, neutrophils are normally found in the bloodstream and are the most abundant type of phagocyte, constituting 50% to 60% of the total circulating white blood cells. One litre of blood contains about five billion neutrophils, which are about 12–15 micrometers in diameter. Once neutrophils have received the signals, it takes them about thirty minutes to leave the blood. Neutrophils do not return to the blood, they turn into pus cells, mature neutrophils are smaller than monocytes, and have a segmented nucleus with several sections, each section is connected by chromatin filaments. Neutrophils do not normally exit the bone marrow until maturity, neutrophils have three strategies for directly attacking micro-organisms, phagocytosis, release of soluble anti-microbials, and generation of neutrophil extracellular traps. Neutrophils are professional phagocytes, they are ferocious eaters and rapidly engulf invaders coated with antibodies and complement, the intracellular granules of the human neutrophil have long been recognized for their protein-destroying and bactericidal properties. Neutrophils can secrete products that stimulate monocytes and macrophages, these secretions increase phagocytosis, neutrophils have two types of granules, primary granules and secondary granules. In addition, secretions from the granules of neutrophils stimulate the phagocytosis of IgG antibody-coated bacteria. The secondary granules contain compounds that are involved in the formation of oxygen compounds, lysozyme. Neutrophil extracellular traps comprise a web of fibers composed of chromatin and serine proteases that trap, trapping of bacteria is a particularly important role for NETs in sepsis, where NET are formed within blood vessels. Eosinophils also have kidney-shaped lobed nuclei, the number of granules in an eosinophil can vary because they have a tendency to degranulate while in the blood stream. A polypeptide called interleukin-5 interacts with eosinophils and causes them to grow and differentiate, basophils are one of the least abundant cells in bone marrow and blood. Like neutrophils and eosinophils, they have lobed nuclei, however, basophils have receptors that can bind to IgE, IgG, complement, and histamine. The cytoplasm of basophils contains an amount of granules, these granules are usually numerous enough to partially conceal the nucleus. Granule contents of basophils are abundant with histamine, heparin, chondroitin sulfate, peroxidase, platelet-activating factor, when an infection occurs, mature basophils will be released from the bone marrow and travel to the site of infection

9.
Erythropoietin
–
Erythropoietin, also known as EPO, hematopoietin, or hemopoietin, is a glycoprotein hormone that controls erythropoiesis, or red blood cell production. It is a cytokine for erythrocyte precursors in the bone marrow, human EPO has a molecular weight of 34 kDa. Erythropoietin is produced by fibroblasts in the kidney in close association with peritubular capillary. It is also produced in cells in the liver. While liver production predominates in the fetal and perinatal period, renal production is predominant during adulthood, exogenous erythropoietin can be provided to people whose kidneys cannot make enough. Recombinant human erythropoietin is produced by recombinant DNA technology in cell culture, several different pharmaceutical agents are available with a variety of glycosylation patterns and are collectively called erythropoiesis-stimulating agents. Major examples are epoetin alfa and epoetin beta, boxed warnings include a risk of death, myocardial infarction, stroke, venous thromboembolism, and tumor recurrence. Erythropoietin is an essential hormone for red blood cell production, without it, definitive erythropoiesis does not take place. Erythropoietin has its effect on red blood cell progenitors and precursors by promoting their survival through protecting these cells from apoptosis. Erythropoietin is the primary factor that cooperates with various other growth factors involved in the development of erythroid lineage from multipotent progenitors. The burst-forming unit-erythroid cells start erythropoietin receptor expression and are sensitive to erythropoietin, subsequent stage, the colony-forming unit-erythroid, expresses maximal erythropoietin receptor density and is completely dependent on erythropoietin for further differentiation. Precursors of red cells, the proerythroblasts and basophilic erythroblasts also express erythropoietin receptor and are affected by it. However this proposal is controversial with numerous studies showing no effect and it is also inconsistent with the low levels of Epo receptors on those cells. Clinical trials in humans with ischemic heart, neural and renal tissues have not demonstrated the same seen in animals. Erythropoietin has been shown to exert its effects by binding to the erythropoietin receptor, EPO is highly glycosylated, with half-life in blood around five hours. EPOs half-life may vary between endogenous and various recombinant versions, additional glycosylation or other alterations of EPO via recombinant technology have led to the increase of EPOs stability in blood. EPO binds to the receptor on the red cell progenitor surface. This initiates the STAT5, PIK3 and Ras MAPK pathways and this results in differentiation, survival and proliferation of the erythroid cell

10.
Tyrosine kinase
–
A tyrosine kinase is an enzyme that can transfer a phosphate group from ATP to a protein in a cell. It functions as an on or off switch in many cellular functions, tyrosine kinases are a subclass of protein kinase. The phosphate group is attached to the amino acid tyrosine on the protein, tyrosine kinases are a subgroup of the larger class of protein kinases that attach phosphate groups to other amino acids. Phosphorylation of proteins by kinases is an important mechanism in communicating signals within a cell and regulating cellular activity, Protein kinases can become mutated, stuck in the on position, and cause unregulated growth of the cell, which is a necessary step for the development of cancer. Therefore, kinase inhibitors, such as imatinib, are often effective cancer treatments, most tyrosine kinases have an associated protein tyrosine phosphatase, which removes the phosphate group. The enzymes fall into two classes, characterised with respect to substrate specificity, serine/threonine-specific, and tyrosine-specific. The term kinase describes a family of enzymes that are responsible for catalyzing the transfer of a phosphoryl group from a nucleoside triphosphate donor, such as ATP. Tyrosine kinases catalyze the phosphorylation of residues in proteins. The phosphorylation of residues in turn causes a change in the function of the protein that they are contained in. Phosphorylation at tyrosine residues controls a wide range of properties in such as enzyme activity, subcellular localization. Finally mutations can cause some tyrosine kinases to become constitutively active, tyrosine kinases function in a variety of processes, pathways, and actions, and are responsible for key events in the body. The receptor tyrosine kinases function in signaling, whereas tyrosine kinases within the cell function in signal transduction to the nucleus. Tyrosine kinase activity in the nucleus involves cell-cycle control and properties of transcription factors, cellular growth and reproduction may rely to some degree on tyrosine kinase. Tyrosine kinase function has been observed in the matrix, which comprises not the chromatin but rather the nuclear envelope. To be specific, Lyn, a type of kinase in the Src family that was identified in the nuclear matrix, Src family tyrosine kinases are closely related but demonstrate a wide variety of functionality. Roles or expressions of Src family tyrosine kinases vary significantly according to type, as well as during cell growth. Lyn and Src family tyrosine kinases in general have been known to function in signal transduction pathways, there is evidence that Lyn is localized at the cell membrane, Lyn is associated both physically and functionally with a variety of receptor molecules. Furthermore, tyrosine kinase activity has been determined to be correlated to cellular transformation and it has also been demonstrated that phosphorylation of a middle-T antigen on tyrosine is also associated with cell transformation, a change that is similar to cellular growth or reproduction

11.
JAK2
–
Janus kinase 2 is a non-receptor tyrosine kinase. JAK2 signaling is activated downstream from the prolactin receptor, the distinguishing feature between janus kinase 2 and other JAK kinases is the lack of Src homology binding domains and the presence of up to seven JAK homology domains. Nonetheless the terminal JH domains retain a level of homology to tyrosine kinase domains. Loss of Jak2 is lethal by embryonic day 12 in mice, JAK2 orthologs have been identified in all mammals for which complete genome data are available. JAK2 gene fusions with the TEL and PCM1 genes have been found in leukemia patients, jak -2 kinase mutations were found to have a high correlation with abnormal heart defects in those of Southeast Asian descent carrying the PYFA gene. Mutations in JAK2 have been implicated in polycythemia vera, essential thrombocythemia, an inhibitor of JAK2-STAT5, AZD1480, was pointed as having activity in primary and CRPC. Jak2 mutation, when demonstrable, is one of the methods of diagnosing polycythemia vera, Janus kinase 2 has been shown to interact with, Prolactin signals through JAK2 are dependent on STAT5, and on the RUSH transcription factors. Janus kinase inhibitor, medical drugs under development Janus Kinase 2 at the US National Library of Medicine Medical Subject Headings

12.
Platelet count
–
Platelets, also called thrombocytes, are a component of blood whose function is to stop bleeding by clumping and clotting blood vessel injuries. Platelets have no nucleus, they are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow. These unactivated platelets are biconvex discoid structures, 2–3 µm in greatest diameter, platelets are found only in mammals, whereas in other animals thrombocytes circulate as intact mononuclear cells. On a stained blood smear, platelets appear as purple spots. The smear is used to examine platelets for size, shape, qualitative number, the ratio of platelets to red blood cells in a healthy adult is 1,10 to 1,20. The main function of platelets is to contribute to hemostasis, the process of stopping bleeding at the site of interrupted endothelium and they gather at the site and unless the interruption is physically too large, they plug the hole. First, platelets attach to substances outside the interrupted endothelium, adhesion, second, they change shape, turn on receptors and secrete chemical messengers, activation. Third, they connect to each other through receptor bridges, aggregation, formation of this platelet plug is associated with activation of the coagulation cascade with resultant fibrin deposition and linking. These processes may overlap, the spectrum is from a predominantly platelet plug, or white clot to a predominantly fibrin clot, the final result is the clot. Some would add the subsequent clot retraction and platelet inhibition as fourth and fifth steps to the completion of the process, low platelet concentration is thrombocytopenia and is due to either decreased production or increased destruction. Elevated platelet concentration is thrombocytosis and is either congenital, reactive, or due to unregulated production, a disorder of platelet function is a thrombocytopathy. An arterial thrombus may partially obstruct blood flow, causing downstream ischemia, or may completely obstruct it, george Gulliver in 1841 drew pictures of platelets using the twin lens microscope invented in 1830 by Joseph Jackson Lister. This microscope improved resolution sufficiently to make it possible to see platelets for the first time, william Addison in 1842 drew pictures of a platelet-fibrin clot. Lionel Beale in 1864 was the first to publish a drawing showing platelets, max Schultze in 1865 described what he called spherules, which he noted were much smaller than red blood cells, occasionally clumped, and were sometimes found in collections of fibrin material. Queens College, Birmingham physician Dr Richard Hill Norris was the first to describe the action of platelets in 1880, giulio Bizzozero in 1882 studied the blood of amphibians microscopically in vivo. He named Schultzs spherules piastrine, little plates, william Osler observed them and, in published lectures in 1886, called them a third corpuscle and a blood plaque and described them as a colorless protoplasmic disc. Thrombocytes are cells found in the blood of non-mammalian vertebrates and they are the functional equivalents of platelets, but circulate as intact mononuclear cells, and are not simply cytoplasmic fragments of bone marrow megakaryocytes. In some contexts, the thrombus is used interchangeably with the word clot

13.
Erythrocyte sedimentation rate
–
The erythrocyte sedimentation rate is the rate at which red blood cells sediment in a period of one hour. It is a common hematology test, and is a measure of inflammation. To perform the test, anticoagulated blood was placed in an upright tube, known as a Westergren tube. Since the introduction of automated analyzers into the laboratory, the ESR test has been automatically performed. The ESR is governed by the balance between pro-sedimentation factors, mainly fibrinogen, and those factors resisting sedimentation, namely the negative charge of the erythrocytes. When an inflammatory process is present, the proportion of fibrinogen in the blood causes red blood cells to stick to each other. The red cells form stacks called rouleaux, which settle faster, rouleaux formation can also occur in association with some lymphoproliferative disorders in which one or more immunoglobulins are secreted in high amounts. Rouleaux formation can, however, be a normal finding in horses, cats. The ESR is increased in inflammation, pregnancy, anemia, autoimmune disorders, infections, some kidney diseases, the ESR is decreased in polycythemia, hyperviscosity, sickle cell anemia, leukemia, low plasma protein and congestive heart failure. The basal ESR is slightly higher in females, in many of these cases, the ESR may exceed 100 mm/hour. It is commonly used for a diagnosis for Kawasakis disease and it may be increased in some chronic infective conditions like tuberculosis. It is also elevated in subacute thyroiditis also known as DeQuervains, the clinical usefulness of ESR is limited to monitoring the response to therapy in certain inflammatory diseases such as temporal arteritis, polymyalgia rheumatica and rheumatoid arthritis. It can also be used as a measure of response in Hodgkins lymphoma. Additionally, ESR levels are used to one of the several possible adverse prognostic factors in the staging of Hodgkins lymphoma. Note, mm/h. = millimeters per hour, westergrens original normal values made no allowance for a persons age. In 1967 it was confirmed that ESR values tend to rise with age, values are increased in states of anemia, and in black populations. The widely used rule calculating normal maximum ESR values in adults is given by a formula devised in 1983, typical normal ranges quoted are, Newborn,0 to 2 mm/h Neonatal to puberty,3 to 13 mm/h, but other laboratories place an upper limit of 20. C-reactive protein is an acute phase protein produced by the liver during an inflammatory reaction, since C-reactive protein levels in the blood rise more quickly after the inflammatory or infective process begins, ESR is often replaced with C-reactive protein measurement

14.
Zeta potential
–
Zeta potential is a scientific term for electrokinetic potential in colloidal dispersions. In the colloidal chemistry literature, it is denoted using the Greek letter zeta. In other words, zeta potential is the difference between the dispersion medium and the stationary layer of fluid attached to the dispersed particle. The zeta potential is caused by the net electrical charge contained within the bounded by the slipping plane. Thus it is used for quantification of the magnitude of the charge. However, zeta potential is not equal to the Stern potential or electric potential in the double layer. Such assumptions of equality should be applied with caution, nevertheless, zeta potential is often the only available path for characterization of double-layer properties. The zeta potential is a key indicator of the stability of colloidal dispersions, the magnitude of the zeta potential indicates the degree of electrostatic repulsion between adjacent, similarly charged particles in a dispersion. For molecules and particles that are enough, a high zeta potential will confer stability. When the potential is small, attractive forces may exceed this repulsion, so, colloids with high zeta potential are electrically stabilized while colloids with low zeta potentials tend to coagulate or flocculate as outlined in the table. Zeta potential is not measurable directly but it can be calculated using theoretical models, electrokinetic phenomena and electroacoustic phenomena are the usual sources of data for calculation of zeta potential. Electrophoresis is used for estimating zeta potential of particulates, whereas streaming potential/current is used for porous bodies, in practice, the Zeta potential of dispersion is measured by applying an electric field across the dispersion. Particles within the dispersion with a zeta potential will migrate toward the electrode of opposite charge with a velocity proportional to the magnitude of the zeta potential and this velocity is measured using the technique of the Laser Doppler Anemometer. Electrophoretic velocity is proportional to electrophoretic mobility, which is the measurable parameter, there are several theories that link electrophoretic mobility with zeta potential. They are briefly described in the article on electrophoresis and in details in many books on colloid, there is an IUPAC Technical Report prepared by a group of world experts on the electrokinetic phenomena. From the instrumental viewpoint, there are two different experimental techniques, microelectrophoresis and electrophoretic light scattering, microelectrophoresis has the advantage of yielding an image of the moving particles. On the other hand, it is complicated by electro-osmosis at the walls of the sample cell, electrophoretic light scattering is based on dynamic light scattering. It allows measurement in a cell which eliminates the problem of electro-osmotic flow for the case of an Uzgiris

15.
Erythrocyte
–
RBCs take up oxygen in the lungs, or gills of fish, and release it into tissues while squeezing through the bodys capillaries. The cytoplasm of erythrocytes is rich in hemoglobin, a biomolecule that can bind oxygen and is responsible for the red color of the cells. In humans, mature red cells are flexible and oval biconcave disks. They lack a nucleus and most organelles, in order to accommodate maximum space for hemoglobin, they can be viewed as sacks of hemoglobin. Approximately 2.4 million new erythrocytes are produced per second in human adults, the cells develop in the bone marrow and circulate for about 100–120 days in the body before their components are recycled by macrophages. Each circulation takes about 60 seconds, approximately a quarter of the cells in the human body are red blood cells. Nearly half of the volume is red blood cells. Red blood cells are known as RBCs, red cells, red blood corpuscles, haematids. Packed red blood cells are red blood cells that have donated, processed. Almost all vertebrates, including all mammals and humans, have red blood cells, red blood cells are cells present in blood in order to transport oxygen. The only known vertebrates without red blood cells are the crocodile icefish, they live in very cold water. While they no longer use hemoglobin, remnants of hemoglobin genes can be found in their genome, oxygen can easily diffuse through the red blood cells cell membrane. Myoglobin, a related to hemoglobin, acts to store oxygen in muscle cells. The color of red cells is due to the heme group of hemoglobin. However, blood can appear bluish when seen through the vessel wall, pulse oximetry takes advantage of the hemoglobin color change to directly measure the arterial blood oxygen saturation using colorimetric techniques. Hemoglobin also has a high affinity for carbon monoxide, forming carboxyhemoglobin which is a very bright red in color. Flushed, confused patients with a reading of 100% on pulse oximetry are sometimes found to be suffering from carbon monoxide poisoning. The red blood cells of mammals are typically shaped as disks, flattened and depressed in the center, with a dumbbell-shaped cross section

16.
Viscosity
–
The viscosity of a fluid is a measure of its resistance to gradual deformation by shear stress or tensile stress. For liquids, it corresponds to the concept of thickness, for example. Viscosity is a property of the fluid which opposes the motion between the two surfaces of the fluid in a fluid that are moving at different velocities. For a given velocity pattern, the stress required is proportional to the fluids viscosity, a fluid that has no resistance to shear stress is known as an ideal or inviscid fluid. Zero viscosity is observed only at low temperatures in superfluids. Otherwise, all fluids have positive viscosity, and are said to be viscous or viscid. A fluid with a high viscosity, such as pitch. The word viscosity is derived from the Latin viscum, meaning mistletoe, the dynamic viscosity of a fluid expresses its resistance to shearing flows, where adjacent layers move parallel to each other with different speeds. It can be defined through the situation known as a Couette flow. This fluid has to be homogeneous in the layer and at different shear stresses, if the speed of the top plate is small enough, the fluid particles will move parallel to it, and their speed will vary linearly from zero at the bottom to u at the top. Each layer of fluid will move faster than the one just below it, in particular, the fluid will apply on the top plate a force in the direction opposite to its motion, and an equal but opposite one to the bottom plate. An external force is required in order to keep the top plate moving at constant speed. The magnitude F of this force is found to be proportional to the u and the area A of each plate. The proportionality factor μ in this formula is the viscosity of the fluid, the ratio u/y is called the rate of shear deformation or shear velocity, and is the derivative of the fluid speed in the direction perpendicular to the plates. Isaac Newton expressed the forces by the differential equation τ = μ ∂ u ∂ y, where τ = F/A. This formula assumes that the flow is moving along parallel lines and this equation can be used where the velocity does not vary linearly with y, such as in fluid flowing through a pipe. Use of the Greek letter mu for the dynamic viscosity is common among mechanical and chemical engineers. However, the Greek letter eta is used by chemists, physicists

17.
Janus kinase
–
Janus kinase is a family of intracellular, nonreceptor tyrosine kinases that transduce cytokine-mediated signals via the JAK-STAT pathway. They were initially named just another kinase 1 and 2 but were published as Janus kinase. The name is taken from the two-faced Roman god of beginnings and endings, Janus, one domain exhibits the kinase activity, while the other negatively regulates the kinase activity of the first. JAK1 and JAK2 are involved in type II interferon signalling, whereas JAK1, mice that do not express TYK2 have defective natural killer cell function. The receptors exist as paired polypeptides, thus exhibiting two intracellular signal-transducing domains, JAKs associate with a proline-rich region in each intracellular domain that is adjacent to the cell membrane and called a box1/box2 region. After the receptor associates with its respective cytokine/ligand, it goes through a conformational change, the activated STATs dissociate from the receptor and form dimers before translocating to the cell nucleus, where they regulate transcription of selected genes. Some examples of the molecules that use the JAK/STAT signaling pathway are colony-stimulating factor, prolactin, growth hormone, examples are tofacitinib and filgotinib, the latter is currently under development by the Belgian firm Galapagos. In 2014 researchers discovered that oral JAK inhibitors, when administered orally could restore hair growth in some subjects, JAKs range from 120-140 kDa in size and have seven defined regions of homology called Janus homology domains 1 to 7. JH1 is the kinase domain important for the activity of the JAK. Phosphorylation of these dual tyrosines leads to the changes in the JAK protein to facilitate binding of substrate. JH2 is a domain, a domain structurally similar to a tyrosine kinase and essential for a normal kinase activity. This domain may be involved in regulating the activity of JH1, the JH3-JH4 domains of JAKs share homology with Src-homology-2 domains

18.
Chemotherapy
–
Chemotherapy is a category of cancer treatment that uses one or more anti-cancer drugs as part of a standardized chemotherapy regimen. Chemotherapy may be given with an intent, or it may aim to prolong life or to reduce symptoms. Chemotherapy is one of the categories of the medical discipline specifically devoted to pharmacotherapy for cancer. Systemic therapy is used in conjunction with other modalities that constitute local therapy for cancer such as radiation therapy. Traditional chemotherapeutic agents are cytotoxic by means of interfering with cell division, to a large extent, chemotherapy can be thought of as a way to damage or stress cells, which may then lead to cell death if apoptosis is initiated. This results in the most common side-effects of chemotherapy, myelosuppression, mucositis, because of the effect on immune cells, chemotherapy drugs often find use in a host of diseases that result from harmful overactivity of the immune system against self. These include rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, vasculitis, there are a number of strategies in the administration of chemotherapeutic drugs used today. Chemotherapy may be given with an intent or it may aim to prolong life or to palliate symptoms. Induction chemotherapy is the first line treatment of cancer with a chemotherapeutic drug and this type of chemotherapy is used for curative intent. Combined modality chemotherapy is the use of drugs with other treatments, such as surgery, radiation therapy. Consolidation chemotherapy is given after remission in order to prolong the overall disease-free time, the drug that is administered is the same as the drug that achieved remission. Intensification chemotherapy is identical to consolidation chemotherapy but a different drug than the induction chemotherapy is used, combination chemotherapy involves treating a patient with a number of different drugs simultaneously. The drugs differ in their mechanism and side-effects, the biggest advantage is minimising the chances of resistance developing to any one agent. Also, the drugs can often be used at lower doses, neoadjuvant chemotherapy is given prior to a local treatment such as surgery, and is designed to shrink the primary tumor. It is also given to cancers with a risk of micrometastatic disease. Adjuvant chemotherapy is given after a local treatment and it can be used when there is little evidence of cancer present, but there is risk of recurrence. It is also useful in killing any cancerous cells that have spread to parts of the body. These micrometastases can be treated with adjuvant chemotherapy and can reduce relapse rates caused by these disseminated cells, maintenance chemotherapy is a repeated low-dose treatment to prolong remission

Red blood cells
–
RBCs take up oxygen in the lungs, or gills of fish, and release it into tissues while squeezing through the bodys capillaries. The cytoplasm of erythrocytes is rich in hemoglobin, a biomolecule that can bind oxygen and is responsible for the red color of the cells. In humans, mature red cells are flexible and oval biconcave disks. They lack a nucle

2.
There is an immense size variation in vertebrate erythrocytes, as well as a correlation between cell and nucleus size. Mammalian erythrocytes, which do not contain nuclei, are considerably smaller than those of most other vertebrates.

3.
Mature erythrocytes of birds have a nucleus, however in the blood of adult females of penguin Pygoscelis papua enucleated red blood cells (B) have been observed, but with very low frequency.

White blood cells
–
White blood cells, also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from multipotent cells in the bone known as hematopoietic stem cells. Leukocytes are found throughout the body, incl

1.
A scanning electron microscope image of normal circulating human blood. In addition to the irregularly shaped leukocytes, both red blood cells and many small disc-shaped platelets are visible.

2.
Monocyte

3.
Neutrophil engulfing anthrax bacteria

Platelets
–
Platelets, also called thrombocytes, are a component of blood whose function is to stop bleeding by clumping and clotting blood vessel injuries. Platelets have no nucleus, they are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow. These unactivated platelets are biconvex discoid structures, 2–3 µm in greatest diame

Asymptomatic
–
In medicine, a disease is considered asymptomatic if a patient is a carrier for a disease or infection but experiences no symptoms. A condition might be if it fails to show the noticeable symptoms with which it is usually associated. Asymptomatic infections are also called subclinical infections, other diseases might be considered subclinical if th

1.
Pulmonary contusion due to trauma is an example of a condition that can be asymptomatic with half of people showing no signs at the initial presentation since such symptoms can take time to develop. The CT scan shows a pulmonary contusion (red arrow) accompanied by a rib fracture (purple arrow).

Prostaglandin
–
The prostaglandins are a group of physiologically active lipid compounds having diverse hormone-like effects in animals. Prostaglandins have been found in almost every tissue in humans and other animals and they are derived enzymatically from fatty acids. Every prostaglandin contains 20 carbon atoms, including a 5-carbon ring and they are a subclas

1.
E1 - Alprostadil

Red blood cell
–
RBCs take up oxygen in the lungs, or gills of fish, and release it into tissues while squeezing through the bodys capillaries. The cytoplasm of erythrocytes is rich in hemoglobin, a biomolecule that can bind oxygen and is responsible for the red color of the cells. In humans, mature red cells are flexible and oval biconcave disks. They lack a nucle

2.
There is an immense size variation in vertebrate erythrocytes, as well as a correlation between cell and nucleus size. Mammalian erythrocytes, which do not contain nuclei, are considerably smaller than those of most other vertebrates.

3.
Mature erythrocytes of birds have a nucleus, however in the blood of adult females of penguin Pygoscelis papua enucleated red blood cells (B) have been observed, but with very low frequency.

Megakaryocyte
–
A megakaryocyte is a large bone marrow cell with a lobulated nucleus responsible for the production of blood thrombocytes, which are necessary for normal blood clotting. Megakaryocytes normally account for 1 out of 10,000 bone marrow cells, owing to variations in combining forms and spelling, synonyms include megalokaryocyte and megacaryocyte. In g

1.
Two megakaryocytes in bone marrow, marked with arrows.

2.
Megakaryocyte

Granulocyte
–
Granulocytes are a category of white blood cells characterized by the presence of granules in their cytoplasm. They are also called polymorphonuclear leukocytes because of the shapes of the nucleus. This distinguishes them from the mononuclear agranulocytes, in common parlance, the term polymorphonuclear leukocyte often refers specifically to neutr

1.
Eosinophilic granulocyte

2.
A neutrophil with a segmented nucleus (center and surrounded by erythrocytes), the intra-cellular granules are visible in the cytoplasm (Giemsa-stained high magnification)

3.
A basophil with lobed nuclei surrounded by erythrocytes

4.
Blood cell lineage

Erythropoietin
–
Erythropoietin, also known as EPO, hematopoietin, or hemopoietin, is a glycoprotein hormone that controls erythropoiesis, or red blood cell production. It is a cytokine for erythrocyte precursors in the bone marrow, human EPO has a molecular weight of 34 kDa. Erythropoietin is produced by fibroblasts in the kidney in close association with peritubu

2.
Erythropoietin

Tyrosine kinase
–
A tyrosine kinase is an enzyme that can transfer a phosphate group from ATP to a protein in a cell. It functions as an on or off switch in many cellular functions, tyrosine kinases are a subclass of protein kinase. The phosphate group is attached to the amino acid tyrosine on the protein, tyrosine kinases are a subgroup of the larger class of prote

1.
Tyrosine-protein kinase zap-70

JAK2
–
Janus kinase 2 is a non-receptor tyrosine kinase. JAK2 signaling is activated downstream from the prolactin receptor, the distinguishing feature between janus kinase 2 and other JAK kinases is the lack of Src homology binding domains and the presence of up to seven JAK homology domains. Nonetheless the terminal JH domains retain a level of homology

1.
PDB rendering based on 2b7a.

Platelet count
–
Platelets, also called thrombocytes, are a component of blood whose function is to stop bleeding by clumping and clotting blood vessel injuries. Platelets have no nucleus, they are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow. These unactivated platelets are biconvex discoid structures, 2–3 µm in greatest diame

Erythrocyte sedimentation rate
–
The erythrocyte sedimentation rate is the rate at which red blood cells sediment in a period of one hour. It is a common hematology test, and is a measure of inflammation. To perform the test, anticoagulated blood was placed in an upright tube, known as a Westergren tube. Since the introduction of automated analyzers into the laboratory, the ESR te

1.
Westergren pipet array on StaRRsed automated ESR analyzer

Zeta potential
–
Zeta potential is a scientific term for electrokinetic potential in colloidal dispersions. In the colloidal chemistry literature, it is denoted using the Greek letter zeta. In other words, zeta potential is the difference between the dispersion medium and the stationary layer of fluid attached to the dispersed particle. The zeta potential is caused

1.
Diagram showing the ionic concentration and potential difference as a function of distance from the charged surface of a particle suspended in a dispersion medium.

Erythrocyte
–
RBCs take up oxygen in the lungs, or gills of fish, and release it into tissues while squeezing through the bodys capillaries. The cytoplasm of erythrocytes is rich in hemoglobin, a biomolecule that can bind oxygen and is responsible for the red color of the cells. In humans, mature red cells are flexible and oval biconcave disks. They lack a nucle

2.
There is an immense size variation in vertebrate erythrocytes, as well as a correlation between cell and nucleus size. Mammalian erythrocytes, which do not contain nuclei, are considerably smaller than those of most other vertebrates.

3.
Mature erythrocytes of birds have a nucleus, however in the blood of adult females of penguin Pygoscelis papua enucleated red blood cells (B) have been observed, but with very low frequency.

Viscosity
–
The viscosity of a fluid is a measure of its resistance to gradual deformation by shear stress or tensile stress. For liquids, it corresponds to the concept of thickness, for example. Viscosity is a property of the fluid which opposes the motion between the two surfaces of the fluid in a fluid that are moving at different velocities. For a given ve

1.
Pitch has a viscosity approximately 230 billion (2.3 × 10 11) times that of water.

2.
Laminar shear of fluid between two plates. Friction between the fluid and the moving boundaries causes the fluid to shear. The force required for this action is a measure of the fluid's viscosity.

3.
Example of the viscosity of milk and water. Liquids with higher viscosities make smaller splashes when poured at the same velocity.

4.
Honey being drizzled.

Janus kinase
–
Janus kinase is a family of intracellular, nonreceptor tyrosine kinases that transduce cytokine-mediated signals via the JAK-STAT pathway. They were initially named just another kinase 1 and 2 but were published as Janus kinase. The name is taken from the two-faced Roman god of beginnings and endings, Janus, one domain exhibits the kinase activity,

1.
Overview of signal transduction pathways involved in apoptosis.

Chemotherapy
–
Chemotherapy is a category of cancer treatment that uses one or more anti-cancer drugs as part of a standardized chemotherapy regimen. Chemotherapy may be given with an intent, or it may aim to prolong life or to reduce symptoms. Chemotherapy is one of the categories of the medical discipline specifically devoted to pharmacotherapy for cancer. Syst

1.
A woman being treated with docetaxel chemotherapy for breast cancer. Cold mittens and wine coolers are placed on her hands and feet to reduce harm to her nails.

1.
Top view of a module base (lid removed) looking into the four separated wells where cell culture inserts would usually sit and be exposed to tobacco smoke or an aerosol for an in-vitro study of the effects.

1.
monocytes under a light microscope from a peripheral blood smear surrounded by red blood cells

2.
A scanning electron microscope (SEM) image of normal circulating human blood. One can see red blood cells, several knobby white blood cells including lymphocytes, a monocyte, a neutrophil, and many small disc-shaped platelets.